PLL Episode 4x10 - The Mirror Has Three Faces

Clues from the episode that Aria isA

The Bell Jar is a novel where the main character is a female writer/poet who descends into mental illness. In a future episode (4x10), Caleb asks Hanna "now you want to go to Radley and ring The Bell Jar. He was referring to Hanna planning to go visit Mona when she is a patient at Radley. The Bell Jar references to both Aria and Mona are even more interesting when you look at the cover of the book. This is the second reference to the Bell Jar. In season 1 when Aria is deciding what to wear to the homecoming dance, Hanna asks her if she wants "hot" or "bell jar".